1. Field of the Invention
This invention relates to air devices for use with aquarium undergravel filters, box filters and sponge filters as opposed to aeration devices which are exterior to the aquarium or mounted to the inside of the aquarium. In particular, the present invention has improved water flow while maintaining simplicity and convenience of operation. It also is economical since it can be used as a lifetime aeration device with minimum maintenance.
2. Description of the Prior Art
There are numerous air devices used for aerating today's aquarium including power heads, air diffusers, and air stones. The air diffusers and air stones are placed inside the aquarium alone or used in addition to filtering units such as box filters, sponge filters and undergravel filters. These units are described in U.S. Pat. Nos. 5,246,282; 5,133,906; 4,776,127; 4,192,255; and 4,655,915.
There are several drawbacks to the general use of these air devices for aquariums. First, the air diffusers are very lightweight and have a tendency to float if not secured. This decreases its aeration effectiveness. Air stones/bubblers, even though they are heavier than the diffusers, have a tendency to become displaced requiring manual placement. Second, these devices become clogged with free floating particles in the air or with algae. Sometimes cleaning the device with a brush is inadequate and soaking the device in a cleansing solution is necessary. Often the device remains clogged and requires replacement. This results in ineffective use of manpower as well as additional expense.
When these devices are used with undergravel filters, box filters and the sponge filters, additional drawbacks become apparent. The major disadvantage of these devices with an undergravel filter is the choking of water/air flow through the lift chamber. This occurs because the device requires space in the lift tube where the water and air also must flow. The effective rate of aeration is reduced because of the inability of the air lift chamber to accommodate the inflow rate of the air entering from the air flow tube. This creates a "bottleneck" effect thus reducing the flow.
Another disadvantage of these devices is the fact the air is released in a direction perpendicular to the natural air flow direction. The air must change directions, reducing the momentum of the air flow and thus the aeration effect is slowed.